DESCRIPTION & OPERATION

Transcription

1 DESCRIPTION & OPERATION 2001 ACCESSORIES/SAFETY EQUIPMENT General Motors Corp. - Air Bag Restraint Systems WARNING: Accidental air bag deployment is possible. Personal injury may result. To avoid injury from accidental air bag deployment, read and carefully follow all WARNINGS and AIR BAG SAFETY PRECAUTIONS. SUPPLEMENTAL INFLATABLE RESTRAINT (SIR) SYSTEM SIR system is designed to supplement protection provided by driver and passenger-side seat belts. A frontal crash of sufficient force up to 30 degrees off center line of vehicle will deploy driver and passenger-side air bags. Steering column and knee bolsters also absorb crash energy. SIR system consists of Sensing and Diagnostic Module (SDM), driver and passenger-side air bag modules, SIR coil assembly, Passenger SIR (PSIR) suppression switch and AIR BAG warning light. SENSING & DIAGNOSTIC MODULE (SDM) SDM monitors vehicle velocity changes to detect frontal crashes which are severe enough to warrant air bag module deployment. When a frontal crash of sufficient force is detected, SDM causes current flow through air bag modules, deploying air bags. SDM also maintains a 23 Volt Loop Reserve (23 VLR) energy supply to provide deployment energy for up to one minute after loss of voltage. Additionally, SDM provides diagnostic monitoring of SIR system electrical components. When a malfunction is detected, SDM sets a Diagnostic Trouble Code (DTC) which can be retrieved using a scan tool. SDM warns driver of system malfunctions by controlling AIR BAG warning light. AIR BAG WARNING LIGHT Ignition switch applies battery voltage to AIR BAG warning light. SDM controls light by providing ground with a light driver. When ignition switch is first turned on, AIR BAG warning light verifies system operation by flashing 7 times and turning off. During vehicle operation, AIR BAG warning light warns driver of malfunctions which could potentially affect SIR system operation.

2 SIR COIL ASSEMBLY SIR coil assembly consists of 2 or more current-carrying coils. Coils are attached to steering column and allow rotation of steering wheel, while maintaining continuous continuity of driverside air bag module deployment loop. AIR BAG MODULES Air bag modules consist of an inflatable bag and an inflator. When vehicle is in an accident of sufficient force, SDM causes current flow through deployment loops. Current passing through inflators ignites inflator charges, producing gas which rapidly inflates air bags. PASSENGER SIR (PSIR) SUPPRESSION SWITCH PSIR suppression switch, also known as disable switch, allows passenger-side air bag module to be deactivated with key. When passenger-side air bag module is deactivated, an LED will be activated as a visual reminder that air bag is deactivated. KNEE BOLSTERS Knee bolsters are used to absorb energy and control forward movement of front passengers. This is accomplished by limiting leg movement during a frontal crash. COMPONENT LOCATIONS COMPONENT LOCATIONS Component AIR BAG warning light Driver air bag module Knee bolsters Passenger air bag module Passenger Supplemental Restraint (PSIR) suppression switch Sensing & Diagnostic Module (SDM) SIR coil Location In instrument cluster On steering wheel Driver & passenger-side lower instrument panel Passenger-side dash Inside glove box Under center of instrument panel Below steering wheel SYSTEM OPERATION CHECK If system is functioning normally, AIR BAG warning light flashes 7 times and then turns off when

3 ignition switch is turned on. System malfunction is indicated when light does not illuminate at all, light comes on while vehicle is driven, light flashes 7 times and remains on, or light does not flash but remains on when ignition switch is turned on. AIR BAG SAFETY PRECAUTIONS Observe the following precautions when working with SIR system: SDM maintains sufficient voltage to cause air bag deployment for up to one minute after ignition switch is turned off, battery is disconnected, or fuse powering SDM is removed. In order to begin servicing immediately, inflator modules must be removed from deployment loop. See DISABLING & ACTIVATING AIR BAG SYSTEM. After repairs, ensure AIR BAG warning light is working properly and no system faults are indicated. See SYSTEM OPERATION CHECK. Always wear safety glasses when servicing or handling an air bag module. Air bag modules must be stored in original special containers until used for service. Store in a clean, dry place, away from sources of extreme heat, sparks, or high electrical energy. Air bag modules or SDMs should not be subjected to temperatures greater than 150 (65 ). Air bag modules, SDM or SIR coil should not be used if they have been dropped from a height of 3 feet (0.9 m) or greater. When placing a live air bag module on a bench or other surface, always make certain that trim cover faces up. This will reduce motion of module if accidentally deployed. After deployment, air bag surface may contain deposits of sodium hydroxide, which can irritate skin. Always wear safety glasses, rubber gloves and long-sleeved shirt during cleanup, and wash hands using mild soap and water. Follow correct disposal procedures. See DISPOSAL PROCEDURES. At no time should any electrical source be allowed near inflator on back of air bag module. Do not apply power to SIR system unless all components are connected or a diagnostic test requests it, as this will set a diagnostic trouble code. When carrying a live air bag module, trim cover should be pointed away from body to minimize injury in case of accidental deployment. Do not attempt to service SDM, SIR coil or air bag modules. If defective, these parts must be replaced. Do not probe a wire through insulator; this damages wire and eventually causes failure due to corrosion. When performing electrical tests, prevent accidental shorting of terminals. Such mistakes can damage fuses or components and may cause a second fault code to set, making diagnosis

4 of original problem more difficult. When using diagnostic tests to diagnose SIR system, under no circumstances should a voltohmmeter, test light or any type of electrical equipment not specified by manufacturer be used. If SIR system is not fully functional for any reason, vehicle should not be driven until system is repaired. DO NOT remove bulbs, modules, sensors or other components or in any way disable system from operating normally. ADJUSTMENTS CENTERING COIL ASSEMBLY NOTE: New coil assemblies are pre-centered and include a centering tab that is removed once coil is installed. Hold coil assembly with face up. Depress spring lock and slowly rotate hub clockwise until hub stops. Coil ribbon should now be wound up snugly against center hub. Rotate coil hub slowly in opposite direction until centering window turns Yellow and both arrows line up. Release spring lock between locking tabs. See Fig. 1.

5 Fig. 1: Centering SIR Coil Assembly Courtesy of GENERAL MOTORS CORP. DISABLING & ACTIVATING AIR BAG SYSTEM CAUTION: Vehicle computer and memory systems may loose memory data when battery is disconnected. Driveability problems may exist until computer systems have completed a relearn cycle. See Computer Relearn Procedures in the Reference Information section. Record preset radio stations and obtain code for theft deterrent-equipped radios before disconnecting battery. DISABLING SYSTEM

6 WARNING: Accidental air bag deployment in possible. Personal injury may result. SDM maintains sufficient voltage to cause air bag deployment for up to one minute after ignition switch is turned off, battery is disconnected, or fuse powering SDM is removed. In order to begin servicing immediately, inflator modules must be removed from deployment loop. NOTE: When SDM fuse is removed and ignition switch is in RUN position, AIR BAG warning light will be on. This does not indicate a system malfunction. 1. Turn steering wheel to place vehicle wheels in straight-ahead position. Turn ignition switch to LOCK position and remove key. 2. Remove right front floor kick-up panel. Remove SDM fuse (15-amp) located in instrument panel fuse block, located in right front footwell. Remove left sound insulator. Remove Connector Position Assurance (CPA) clip and disconnect driver-side air bag module Yellow 2-pin connector, located at base of steering column. See Fig. 2. Remove CPA clip and disconnect passenger-side air bag module Yellow 2-pin connector, located to the right of steering column. See Fig. 3. System is now disabled.

7 Fig. 2: Locating Driver-side Air Bag Yellow 2-pin Connector Courtesy of GENERAL MOTORS CORP.

8 Fig. 3: Locating Passenger-side Air Bag Yellow 2-pin Connector Courtesy of GENERAL MOTORS CORP. ACTIVATING SYSTEM With key removed from ignition switch, connect driver and passenger-side air bag Yellow 2-pin connectors. See Fig. 2 & Fig. 3. Install CPA clips. Install left sound insulator. Install SDM fuse. Install front floor kick-up panel. Check system for proper operation. See SYSTEM OPERATION CHECK. DISPOSAL PROCEDURES WARNING: Accidental air bag deployment in possible. Personal injury may result. To prevent accidental deployment and personal

9 injury, deploy air bags before disposal. DO NOT dispose of undeployed air bag modules at normal refuse locations. Undeployed air bag modules contain substances that can cause severe illness or personal injury if sealed container is damaged during disposal. NOTE: If vehicle is to be scrapped, perform on-vehicle air bag deployment procedure. ON-VEHICLE DEPLOYMENT 1. Before proceeding, see AIR BAG SAFETY PRECAUTIONS. Turn ignition switch off, remove key and put on safety glasses. Disconnect driver and passenger-side air bag module connectors. See Fig. 2 & Fig. 3. Cut air bag module harness connectors from vehicle leaving at least 6" (152 mm) of wire at each connector. 2. Strip 0.50" (13 mm) of insulation from each connector wire lead. Cut 2 15-foot (4.6 m) deployment wires from 18-gauge multi-strand wire. Strip 0.50" (13 mm) of insulation from both ends of wires. Twist wires together at one end to short. 3. Twist together one connector wire lead to other end of each deployment wire. See Fig. 4. Bend twisted connection flat and wrap tightly with electrical tape to insulate. Repeat this step for remaining connector wire lead. 4. Remove all loose objects from front seat, and ensure no one is in vehicle. Connect deployment harness to driver-side air bag module connector. Stretch wires away from car as far as possible. 5. Repeat steps 1) through 4) for passenger-side air bag module. Cover windshield and front door openings with a drop cloth. 6. Separate wire ends. Connect wire ends to a 12-volt battery. Air bags should deploy. Disconnect wires from battery. DO NOT touch air bag module area for at least 10 minutes due to heat generated during deployment. Wear gloves and safety glasses before handling deployed air bag module. Wash hands with mild soap and water afterward. Deployed air bag modules can be disposed of like any other part. Repeat deployment procedure for passenger-side air bag. 7. If air bag modules do not deploy, carefully remove from vehicle. See AIR BAG MODULES under REMOVAL & INSTALLATION. Temporarily store module with trim facing up. Contact manufacturer for proper disposal instructions.

10 OFF-VEHICLE DEPLOYMENT 2001 Chevrolet Corvette Fig. 4: Preparing Deployment Harness For On-vehicle Deployment Courtesy of GENERAL MOTORS CORP.

11 1. Before proceeding, see AIR BAG SAFETY PRECAUTIONS. Turn ignition switch off, remove key and put on safety glasses. Short 2 SIR Deployment Harness (J-38826) leads together by fully seating one banana plug into the other. Connect appropriate pigtail adapter to SIR deployment harness. See Fig Remove driver-side air bag module. See AIR BAG MODULES under REMOVAL & INSTALLATION. Remove horn lead, redundant steering wheel control leads, horn buttons and steering wheel control buttons from air bag module, if applicable. 3. Place driver-side air bag module with vinyl trim cover facing up, on shop floor or other surface (preferably paved surface outdoors) away from any loose or flammable objects. Clear space at least 6 feet (1.8 m) in diameter around air bag. Extend SIR deployment harness and pigtail adapter to full length from air bag module. Place a 12-volt battery near shorted end of SIR deployment harness. 4. Connect air bag module to pigtail adapter on SIR deployment harness. See Fig. 5. Ensure area around air bag module is clear of people or loose objects. Verify that air bag module is resting with trim cover facing up. 5. Separate 2 banana plugs on SIR deployment harness. Connect SIR deployment harness wires to battery. See Fig. 5. Air bag module should deploy immediately. If air bag module does not deploy, go to step 7. Disconnect SIR deployment harness from battery. Short 2 SIR deployment harness leads together. DO NOT touch metal surfaces of air bag module for at least 10 minutes due to heat generated during deployment. Wear gloves and safety glasses when handling deployed air bag module. Wash hands with mild soap and water after handling. Dispose of deployed air bag module as you would any other part. Inspect pigtail adapter and SIR deployment harness for damage after each use. 6. Repeat steps 2) through 5) for passenger-side air bag module. Prior to deployment, ensure that passenger-side air bag module is mounted in Deployment Fixture (J39401-B). 7. Ensure that SIR deployment harness is disconnected from battery and that 2 banana plugs have been shorted together. Disconnect pigtail adapter from air bag module. Temporarily store air bag module with trim cover facing up. Contact manufacturer for proper disposal instructions.

12 Fig. 5: Preparing Deployment Harness For Off-vehicle Deployment Courtesy of GENERAL MOTORS CORP. POST-COLLISION INSPECTION When a vehicle has been involved in a collision, certain components of the passive restraint system must be inspected or replaced. See AIR BAG/SRS COMPONENT INSPECTION & REPLACEMENT TABLES article in the GENERAL INFORMATION section. REMOVAL & INSTALLATION SENSING & DIAGNOSTIC MODULE (SDM) Removal WARNING: Accidental air bag deployment in possible. Personal injury may result. Failure to follow service precautions may result in air bag deployment and personal injury. See AIR BAG SAFETY PRECAUTIONS. After component replacement, check system operation. See SYSTEM OPERATION CHECK.

13 1. Before proceeding, see AIR BAG SAFETY PRECAUTIONS. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. 2. Remove accessory trim plate. Remove heater and A-C control panel. Remove Connector Position Assurance (CPA) clip from Sensing and Diagnostic Module (SDM) connector and disconnect SDM harness connector from SDM. See Fig Remove mounting bolts and remove SDM from instrument panel center support. Installation 1. To install, reverse removal procedure. Tighten SDM bolts to specification. See TORQUE SPECIFICATIONS. 2. Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. Check system for proper operation. See SYSTEM OPERATION CHECK.

14 Fig. 6: Identifying Sensing & Diagnostic Module (SDM) Courtesy of GENERAL MOTORS CORP. STEERING WHEEL Removal 1. Before proceeding, see AIR BAG SAFETY PRECAUTIONS. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM.

15 2. Remove driver-side air bag module. See AIR BAG MODULES. Remove steering wheel nut and discard. Using Steering Wheel Puller (J-1859-A) and Puller Legs (J-42120), remove steering wheel. Installation 1. To install, reverse removal procedure. Use new steering wheel nut and tighten to specification. See TORQUE SPECIFICATIONS. Install driver-side air bag module. See AIR BAG MODULES. 2. Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. Check system for proper operation. See SYSTEM OPERATION CHECK. SIR COIL ASSEMBLY Removal 1. Before proceeding, see AIR BAG SAFETY PRECAUTIONS. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. 2. Remove driver-side air bag. See AIR BAG MODULES. Remove steering wheel. See STEERING WHEEL. Remove upper and lower steering column covers. 3. Remove wire harness straps from steering wheel column wire harness. Disconnect SIR coil connectors. See Fig. 7. Remove retaining ring. Remove SIR coil from steering shaft. Installation 1. Center SIR coil if necessary. See CENTERING COIL ASSEMBLY under ADJUSTMENTS. Slide SIR coil onto steering shaft. Install retaining ring. 2. Connect SIR coil connectors. Install wire harness straps Install upper and lower steering column shrouds. Install steering wheel and driver-side air bag. Tighten nuts and bolts to specification. See TORQUE SPECIFICATIONS. Activate air bag system. See ACTIVATING SYSTEM under DISABLING & ACTIVATING AIR BAG SYSTEM. Check system for proper operation. See SYSTEM OPERATION CHECK.

16 1. Before proceeding, see AIR BAG SAFETY PRECAUTIONS. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM Chevrolet Corvette Fig. 7: Identifying SIR Coil Assembly Courtesy of GENERAL MOTORS CORP. AIR BAG MODULES Removal Driver-side

17 2. Remove 4 bolts retaining driver-side air bag module to steering wheel. Partially remove air bag module from steering wheel. See Fig. 8. Remove Connector Position Assurance (CPA) clip and disconnect air bag module connector. Disconnect horn wiring harness and ground lead from steering column. Remove driver-side air bag module from vehicle. Installation To install, reverse removal procedure. See Fig. 8. Tighten air bag module bolts to specification. Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. Check system for proper operation. See SYSTEM OPERATION CHECK.

18 Fig. 8: Identifying Driver-side Air Bag Courtesy of GENERAL MOTORS CORP. Removal Passenger-side 1. Before proceeding, see AIR BAG SAFETY PRECAUTIONS. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. 2. Remove instrument panel upper trim panel. See INSTRUMENT PANEL TRIM PAD. Remove Connector Position Assurance (CPA) clip and disconnect passenger-side air bag module Yellow 2-pin connector. Remove nuts securing air bag module to instrument panel bracket. Remove passenger-side air bag module. See Fig. 9. Installation To install, reverse removal procedure. Tighten air bag module mounting nuts to specification. See TORQUE SPECIFICATIONS. Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. Check system for proper operation. See SYSTEM OPERATION CHECK.

19 Fig. 9: Identifying Passenger-side Air Bag Module Courtesy of GENERAL MOTORS CORP. SIR LED MODULE Removal & Installation 1. Before proceeding, see AIR BAG SAFETY PRECAUTIONS. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. 2. Open center console compartment door. Lift up on accessory trim plate to gain access to LED module electrical connector. Disconnect LED module from wiring harness connector. Use Terminal Extractor (J A) to remove LED terminals from LED connector.

20 3. To install, reverse removal procedure. Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. Check system for proper operation. See SYSTEM OPERATION CHECK. PASSENGER SIR (PSIR) SUPPRESSION SWITCH Removal & Installation 1. Before proceeding, see AIR BAG SAFETY PRECAUTIONS. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. 2. Open glove compartment door. Using a small, flat bladed screwdriver, carefully pry PSIR suppression switch from switch mounting plate. Remove Connector Position Assurance (CPA) clip and disconnect PSIR electrical connector. 3. To install, reverse removal procedure. Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. Check system for proper operation. See SYSTEM OPERATION CHECK. INSTRUMENT PANEL TRIM PAD Removal 1. Before proceeding, see AIR BAG SAFETY PRECAUTIONS. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. 2. Remove center console door from center console. Using flat-blade screwdriver, carefully pry traction control and ride control switch from center console. Disconnect electrical connector and remove switch. 3. Pry console retaining nut covers from center console. Remove 4 rear console retaining nuts. Remove front console retaining nuts. Remove instrument panel trim plate. Lift front console panel and pull rear console panel rearward to release from instrument panel trim plate. 4. Disconnect electrical accessory plug connector. Unscrew plug retainer from plug and remove plug from console. Disconnect fuel door release and rear lift window release (if equipped) switch connectors. Turn console over and release switch tabs. Remove switch and center console from vehicle. 5. Apply parking brake. Shift transmission lever to 2 position (automatic transmission) or 4 position (manual transmission). Push shift control boot in toward shift control lever and release retaining tabs to instrument panel trim plate. Turn shift lever boot and push inside instrument panel trim plate. 6. Remove ashtray and accessory trim plate from instrument panel trim plate. Remove screws in ashtray well securing instrument panel trim plate. Pull both sides of trim plate out and

21 pull rearward. Disconnect cigar lighter connector and remove trim plate from vehicle. 7. Using flat-blade screwdriver, pry out fog light and trunk release switches from lower left instrument panel. Remove knee bolster retaining bolt from switch well. Remove 2 lower knee bolster bolts. Pull knee bolster rearward to release locking tabs. Disconnect air temperature sensor connector (if equipped). Remove knee bolster from vehicle. 8. Remove glove box door retaining screw covers. Disconnect glove box light switch connector. Remove 4 screws securing glove box to instrument panel. Remove glove box. 9. Using flat-blade screwdriver, pry defroster grille away from trim pad along front of defroster grille. Lift defroster grille out of instrument panel. Rotate sunload and Daytime Running Lights (DRL) sensors and remove from defrost grille. Lay sensors in defrost duct. 10. Remove A-pillar trim moldings. Remove 4 bolts securing upper instrument panel trim pad to defroster duct. See Fig. 10. Remove 7 bolts securing instrument panel trim pad to hinge pillars, cluster bezel, knee bolster bracket and passenger-side air bag module bracket. 11. Tilt steering wheel down fully. Lift rear edge of instrument panel trim pad about 2" (50 mm) to clear air distribution duct. Carefully pull trim pad away from windshield, guiding panel past left and right-side hinge pillars. Disconnect hazard warning switch connector and remove instrument panel trim pad from vehicle. Installation 1. To install, reverse removal procedure. Tighten instrument panel trim pad bolts to specification. See TORQUE SPECIFICATIONS. 2. Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. Check system for proper operation. See SYSTEM OPERATION CHECK.

22 Fig. 10: Identifying Instrument Panel Trim Pad Courtesy of GENERAL MOTORS CORP. DIAGNOSTICS WARNING: Failure to follow service precautions may result in air bag deployment and personal injury. See AIR BAG SAFETY PRECAUTIONS. After component replacement, check system operation. See SYSTEM OPERATION CHECK. DIAGNOSTIC TROUBLE CODES (DTCS) Sensing & Diagnostic Module (SDM) provides a record of DTCs, stored according to type. SDM performs diagnostic monitoring of SIR system electrical components and sets a DTC when a malfunction is detected. Current DTCs are stored in SDM and are erased when fault is corrected. Current DTCs can be read using a scan tool such as Tech 2.

23 SCAN TOOL DIAGNOSTICS Scan Tool (Tech 2) reads and clears current and history codes. Ensure scan tool contains correct software cartridge for SIR diagnostics. To use scan tool, connect it to Data Link Connector (DLC), located below steering column. Connect scan tool to power source and turn ignition switch to RUN position. Follow scan tool manufacturer instructions for communication with SIR system. DIAGNOSTIC PROCEDURES Diagnostic procedures are designed to find and repair SIR malfunctions. It is important to use diagnostic tests and follow sequence listed below: Perform SIR System Diagnostic Check SIR diagnostic system check should always be starting point for any SIR diagnostics. It checks for proper AIR BAG warning light operation and SIR trouble codes using both flash code and scan tool methods. See SIR DIAGNOSTIC SYSTEM CHECK under DIAGNOSTIC TESTS. Refer To Proper Diagnostic Test SIR diagnostic system check indicates correct test to diagnose SIR problems. Bypassing procedures may result in extended diagnostic time, incorrect diagnosis and incorrect parts replacement. Repeat SIR Diagnostic System Check Performing SIR diagnostic system check after all repair or diagnostic procedures ensures that repair has been made correctly and that no other conditions exist. DIAGNOSTIC TESTS NOTE: AIR BAG warning light will set if serial data communication is shorted to ground or voltage or if communication is lost between SDM and instrument cluster. DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION Trouble Code Possible Cause DTC B0016 Passenger deployment loop resistance low DTC B0017 Passenger deployment loop open DTC B0018 Passenger deployment loop short to ground-voltage

24 DTC B0022 DTC B0024 DTC B0026 DTC B0051 DTC B0053 DTC B0090 DTC B0091 DTC B1001 Driver deployment loop resistance low Driver deployment loop short to ground-voltage Driver deployment loop open Deployment commanded Deployment commanded with loop malfunction Active switch voltage out of range Active switch: Wrong state Option configuration error CONNECTOR IDENTIFICATION NOTE: Refer to illustrations to identify SIR connector terminals. See Fig. 11 through Fig. 15. Fig. 11: Identifying SDM Connector Terminals Courtesy of GENERAL MOTORS CORP.

25 Fig. 12: Identifying SIR Coil Connector Terminals Courtesy of GENERAL MOTORS CORP.

26 Fig. 13: Identifying Passenger-side Air Bag Connector Terminals Courtesy of GENERAL MOTORS CORP.

27 Fig. 14: Identifying Passenger SIR (PSIR) Suppression Switch Terminals Courtesy of GENERAL MOTORS CORP.

28 Fig. 15: Identifying SIR LED Module Terminals Courtesy of GENERAL MOTORS CORP. SIR DIAGNOSTIC SYSTEM CHECK Circuit Description Ignition switch supplies ignition positive voltage to Sensing and Diagnostic Module (SDM) terminal A1 via SDM fuse. When ignition switch is turned to RUN position, SDM responds by performing tests on SIR system while flashing AIR BAG warning light 7 times. If system is okay, AIR BAG warning light will turn off. Diagnostic Aids WARNING: To avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic tests. Carefully follow all instructions.

29 Diagnostic Procedure 2001 Chevrolet Corvette When an intermittent condition is suspected due to a customer complaint that cannot be duplicated or by a DTC that is retrieved as a history DTC, an intermittent condition may exist. Intermittent conditions are usually caused by faulty terminal connections or wiring circuit problems. Diagnostic Procedure 1. Install scan tool to Data Link Connector (DLC), located near base of steering column. If scan tool powers up, go to next step. If scan tool does not power up, inspect and repair data link communications circuits. 2. If scan tool communicates with SDM, go to next step. If scan tool does not communicate with SDM, inspect and repair data link communications circuits. 3. If scan tool displays SIR DTCs, go to next step. If scan tool does not display any DTCs, inspect vehicle for damage to wiring system, visible body damage, faulty or intermittent electrical connections, or addition of aftermarket devices which could affect SIR operation. Diagnose air bag warning light problems. See AIR BAG WARNING LIGHT CIRCUIT MALFUNCTION. 4. If scan tool displays any DTCs that begin with "U", inspect and repair applicable Class 2 Data Link Communication circuit or component. If no DTCs are displayed that begin with "U", go to next step. 5. Diagnose and repair applicable SIR DTC. See DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION table. AIR BAG WARNING LIGHT CIRCUIT MALFUNCTION Circuit Description Ignition switch supplies ignition positive voltage to Sensing and Diagnostic Module (SDM) terminal A1 via SDM fuse. When ignition switch is turned to RUN position, SDM responds by performing tests on SIR system and then flashing AIR BAG warning light 7 times. If system is okay, AIR BAG warning light will turn off. Diagnostic Aids Condition could be caused by an internal Instrument Panel Cluster (IPC) or SDM malfunction. High voltage could also cause condition. NOTE: For circuit number and wire color identification, see WIRING DIAGRAMS.

30 DTC B0016 : PASSENGER DEPLOYMENT LOOP RESISTANCE LOW 2001 Chevrolet Corvette 1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to SIR DIAGNOSTIC SYSTEM CHECK. 2. Observe AIR BAG warning light while turning ignition switch on. If AIR BAG warning light flashes 7 times, go to next step. If AIR BAG warning light does not flash 7 times, go to step If AIR BAG warning light goes off after flashing 7 times, inspect circuits for intermittent condition and repair. Go to step 14. If AIR BAG warning light does not go off, go to step Replace instrument panel cluster. Go to step Using scan tool, attempt to communicate with IPC. If scan tool communicates with IPC, go to next step. If scan tool does not communicate with IPC, inspect and repair Class 2 data link communication circuits. Go to step Observe SIR data list display on scan tool. If voltage is greater than 9 volts, go to next step. If voltage is less than 9 volts, go to step If voltage is greater than 16 volts, inspect and repair charging system. Go to step 14. If voltage is less than 16 volts, go to step Turn ignition off. Disconnect SDM connector. If connector shows signs of corrosion, poor connections or other damage, go to step 12. If connector is okay, go to next step. 9. Remove SDM fuse from fuse block, located in right front foot well. Using Digital Multimeter (J-39200), measure continuity of circuit Press MIN MAX button on DMM. Connect leads of DMM to appropriate terminals. If low or no resistance is indicated, go to next step. If low or no resistance is not indicated, repair open or high resistance in circuit Go to step Using Digital Multimeter (J-39200), measure continuity of battery- to-sdm fuse circuit. If low or no resistance is indicated, go to next step. If low or no resistance is not indicated, repair open or high resistance in circuit. Go to step Using Digital Multimeter (J-39200), measure continuity between SDM case and ground. Press MIN MAX button on DMM. Connect leads of DMM to SDM case and ground point. If low or no resistance is indicated, go to step 13. If low or no resistance is not indicated more, repair high resistance. Go to step Replace SDM connector. See WIRE REPAIR. Go to step Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under REMOVAL & INSTALLATION. Go to next step. 14. Reconnect all SIR system components. Ensure that all components are properly mounted. Go to SIR DIAGNOSTIC SYSTEM CHECK.

31 1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to SIR DIAGNOSTIC SYSTEM CHECK. 2. Turn ignition off. Disconnect passenger-side air bag module connector, located behind glove box. If connector is damaged or corroded, go to next step. If connector is okay, go to step If harness side of connector is damaged, replace connector. See WIRE REPAIR. Go to step 11. If passenger-side air bag connector is damaged, replace passenger-side air bag module. See AIR BAG MODULES under REMOVAL & INSTALLATION. Go to step Reconnect air bag module connector. Ensure CPA clip is installed correctly. Turn ignition on. Using scan tool, check for SIR DTCs. If DTC B0016 is retrieved, go to next step. If 2001 Chevrolet Corvette Circuit Description When ignition switch is turned on, Sensing and Diagnostic Module (SDM) tests deployment loop to check for circuit continuity and shorts to ground or voltage. Conditions For Setting DTC DTC sets when passenger-side air bag module deployment loop resistance is less than 1.3 ohms for 500 milliseconds. Action Taken SDM turns on AIR BAG warning light and sets DTC. Conditions For Clearing DTC DTC will clear when condition responsible for setting DTC no longer exists and CLEAR CODES command is issued via scan tool. History DTC will clear once 255 malfunction free ignition cycles have occurred. Diagnostic Aids Condition could be caused by a short between circuits 1403 and circuit 1404 or by malfunctioning shorting bar on passenger-side air bag connector. A malfunctioning passenger-side air bag module or SDM could also cause condition. NOTE: For circuit number and wire color identification, see WIRING DIAGRAMS Diagnostic Procedure

32 DTC B0016 is not retrieved, go to DIAGNOSTIC AIDS. 5. Turn ignition off. Disconnect passenger air bag module connector. Install SIR Driver- Passenger Load Tool (J A) to harness connector. Turn ignition on. Using scan tool, check for SIR DTCs. If DTC B0016 is retrieved, go to next step. If DTC B0016 is retrieved, replace passenger-side air bag module. See AIR BAG MODULES under REMOVAL & INSTALLATION. Go to step Turn ignition off. Disconnect SDM connector. If connector shows signs of corrosion or other damage, go to step 9. If connector is okay, to go next step. 7. Using Digital Multimeter (J-39200), check resistance between SDM terminals A3 and A8. If resistance is less than infinite, go to next step. If resistance is infinite, go to step Turn ignition off. Repair short between circuits 1403 and See WIRE REPAIR. Go to step Replace SDM connector. See WIRE REPAIR. Go to step Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under REMOVAL & INSTALLATION. Go to next step. 11. Reconnect all SIR components. Ensure that all components are properly mounted. Clear all SIR DTCs. Go to SIR DIAGNOSTIC SYSTEM CHECK. DTC B0017 : PASSENGER DEPLOYMENT LOOP OPEN Circuit Description When ignition switch is turned on, Sensing and Diagnostic Module (SDM) tests deployment loop to check for circuit continuity and shorts to ground or voltage. Conditions For Setting DTC DTC sets when passenger deployment loop resistance is 6 ohms for 300 milliseconds or when passenger-side air bag module deployment loop high side voltage is less than 2 volts and deployment loop resistance is more than 3.7 ohms for 500 milliseconds. Action Taken SDM turns on AIR BAG warning light and sets DTC. Conditions For Clearing DTC DTC will clear when condition responsible for setting DTC no longer exists and CLEAR CODES command is issued via scan tool. History DTC will clear once 255 malfunction free ignition cycles have occurred.

33 Diagnostic Aids Condition could be caused by an open or poor connection in circuits 1403 or A malfunctioning SDM or passenger-side air bag module could also cause condition. NOTE: For circuit number and wire color identification, see WIRING DIAGRAMS. Diagnostic Procedure 1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to SIR DIAGNOSTIC SYSTEM CHECK. 2. Turn ignition off. Disconnect passenger-side air bag module connector, located behind glove box. If connector is damaged or corroded, go to next step. If connector is okay, go to step If harness side of connector is damaged, replace connector. See WIRE REPAIR. Go to step 13. If passenger-side air bag connector is damaged, replace passenger-side air bag module. See AIR BAG MODULES under REMOVAL & INSTALLATION. Go to step Reconnect air bag module connector. Ensure CPA clip is installed correctly. Turn ignition on. Using scan tool, check for SIR DTCs. If DTC B0017 is retrieved, go to next step. If DTC B0017 is not retrieved, go to DIAGNOSTIC AIDS. 5. Turn ignition off. Disconnect passenger-side air bag module connector. Install SIR Driver- Passenger Load Tool (J A) to harness connector. Turn ignition on. Using scan tool, check for SIR DTCs. If DTC B0017 is retrieved, go to next step. If DTC B0017 is not retrieved, replace passenger-side air bag module. See AIR BAG MODULES under REMOVAL & INSTALLATION. Go to step Turn ignition off. Disconnect SDM harness connector. If connector shows signs of corrosion or other damage, go to step 11. If connector is okay, to go next step. 7. Using Digital Multimeter (J-39200), check continuity between SDM connector terminal A3 and passenger-side air bag harness connector terminal "A". Press MIN MAX button on DMM. Connect leads of DMM to appropriate terminals. If low or no resistance is indicated, go to step 9. If low or no resistance is not indicated on DMM, go to next step. 8. Repair open or high resistance in circuit See WIRE REPAIR. Go to step Check continuity between SDM connector terminal A8 and passenger-side air bag harness connector terminal "B". Press MIN MAX button on DMM. Connect leads of DMM to appropriate terminals. If low or no resistance is not indicated on DMM, go to next step. If low or no resistance is indicated on DMM, go to step 12.

34 1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to SIR DIAGNOSTIC SYSTEM CHECK. 2. Turn ignition off. Disconnect passenger-side air bag module connector, located behind glove 2001 Chevrolet Corvette 10. Repair open or high resistance in circuit See WIRE REPAIR. Go to step Replace SDM connector. See WIRE REPAIR. Go to step Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under REMOVAL & INSTALLATION. Go to next step. 13. Reconnect all SIR components. Ensure that all components are properly mounted. Clear all SIR DTCs. Go to SIR DIAGNOSTIC SYSTEM CHECK. DTC B0018 : PASSENGER DEPLOYMENT LOOP SHORT TO GROUND-VOLTAGE Circuit Description When ignition switch is turned on, Sensing and Diagnostic Module (SDM) tests deployment loop to check for circuit continuity and shorts to ground or voltage. Conditions For Setting DTC DTC sets when passenger-side air bag module deployment loop high side voltage is more than 6 volts for 300 milliseconds or when high side voltage is less than 2 volts and deployment loop resistance is less than 3.7 ohms for 300 milliseconds. Action Taken SDM turns on AIR BAG warning light and sets DTC. Conditions For Clearing DTC DTC clears when CLEAR CODES is issued via scan tool. History DTC will be clear once 255 malfunction free ignition cycles have occurred. Diagnostic Aids Condition could be caused by a short to ground or voltage in circuits 1403 or A malfunctioning SDM or passenger-side air bag module could also cause condition. NOTE: For circuit number and wire color identification, see WIRING DIAGRAMS. Diagnostic Procedure

35 box. If connector is damaged or corroded, go to next step. If connector is okay, go to step If harness side of connector is damaged, replace connector. See WIRE REPAIR. Go to step 17. If passenger-side air bag connector is damaged, replace passenger-side air bag module. See AIR BAG MODULES under REMOVAL & INSTALLATION. Go to step Reconnect air bag module connector. Ensure CPA clip is installed correctly. Turn ignition on. Using scan tool, check for SIR DTCs. If DTC B0018 is retrieved, go to next step. If DTC B0018 is not retrieved, go to DIAGNOSTIC AIDS. 5. Turn ignition off. Disconnect passenger-side air bag module connector. Install SIR Driver- Passenger Load Tool (J A) to harness connector. Turn ignition on. Using scan tool, check for SIR DTCs. If DTC B0018 is retrieved, go to next step. If DTC B0018 is not retrieved, replace passenger-side air bag module. See AIR BAG MODULES under REMOVAL & INSTALLATION. Go to step Turn ignition off. Disconnect SDM harness connector. If connector shows signs of corrosion or other damage, go to step 15. If connector is okay, to go next step. 7. Using Digital Multimeter (J-39200), check resistance between SDM connector terminal A3 and ground. If resistance is not infinite, go to next step. If resistance is infinite, go to step Repair short to ground in circuit See WIRE REPAIR. Go to step Using Digital Multimeter (J-39200), check resistance between SDM connector terminal A8 and ground. If resistance is not infinite, go to next step. If resistance is infinite, go to step Repair short to ground in circuit See WIRE REPAIR. Go to step Turn ignition on. Using Digital Multimeter (J-39200), measure voltage between SDM harness connector terminal A3 and ground. If voltage is one volt or more, go to next step. If voltage is less than one volt, go to step Repair short to voltage in circuit See WIRE REPAIR. Go to step Using Digital Multimeter (J-39200), measure voltage between SDM connector terminal A8 and ground. If voltage is one volt or more, go to next step. If voltage is less than one volt, go to step Repair short to voltage in circuit See WIRE REPAIR. Go to step Replace SDM connector. See WIRE REPAIR. Go to step Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under REMOVAL & INSTALLATION. Go to next step. 17. Reconnect all SIR components. Ensure that all components are properly mounted. Clear all SIR DTCs. Go to SIR DIAGNOSTIC SYSTEM CHECK.

36 DTC B0022 : DRIVER DEPLOYMENT LOOP RESISTANCE LOW Circuit Description When ignition switch is turned on, Sensing and Diagnostic Module (SDM) tests deployment loop to check for circuit continuity and shorts to ground or voltage. Conditions For Setting DTC DTC sets when driver deployment loop resistance is less than 1.3 ohms for 300 milliseconds. Action Taken SDM turns on AIR BAG warning light and sets DTC. Conditions For Clearing DTC DTC clears when CLEAR CODES command is issued via scan tool. History DTC clears when 255 malfunction-free ignition cycles have occurred. Diagnostic Aids Condition could be caused by a short between circuits 347 and 348, or by a shorting bar on driver-side air bag connector or SIR coil connector. A malfunctioning SDM could also cause condition. NOTE: For circuit number and wire color identification, see WIRING DIAGRAMS. Diagnostic Procedure 1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to SIR DIAGNOSTIC SYSTEM CHECK. 2. Turn ignition off. Disconnect driver-side air bag wire harness-to-sir coil connector, located near base of steering column. If connector shows signs of corrosion, damaged terminals or poor connections, go to next step. If connector is okay, go to step If harness side of connector is damaged, replace harness connector. See WIRE REPAIR. Go to step 14. If SIR coil side of connector is damaged, replace SIR coil. See SIR COIL ASSEMBLY under REMOVAL & INSTALLATION. Go to step Reconnect driver-side air bag wire harness-to-sir coil connector. Ensure Connector Position Assurance (CPA) clip is installed correctly. Turn ignition on. Using scan tool, check for SIR DTCs. If DTC B0022 is retrieved, go to next step. If DTC B0022 is not

37 DTC sets when driver-side air bag module deployment loop high side voltage is more than 6 volts 2001 Chevrolet Corvette retrieved, go to DIAGNOSTIC AIDS. 5. Turn ignition off. Disconnect driver-side air bag wire harness-to-sir coil connector. Install SIR Driver-Passenger Load Tool (J A) using Load Tool Adapter (J ) to harness connector. Turn ignition on. Using scan tool, check for SIR DTCs. If DTC B0022 is retrieved, go to step 9. If DTC B0022 is not retrieved, go to next step. 6. Turn ignition off. Remove SIR Driver-Passenger Load Tool (J A) and Load Tool Adapter (J ) from connector. Reconnect driver-side air bag wire harness-to-sir coil connector. Remove driver-side air bag module. See AIR BAG MODULES under REMOVAL & INSTALLATION. Install SIR Driver-Passenger Load Tool (J A) using Load Tool Adapter (J A) to upper SIR coil-to-air bag module connector. Turn ignition on. Using scan tool, check for SIR DTCs. If DTC B0022 is retrieved, go to step 8. If DTC B0022 is not retrieved, go to next step. 7. Turn ignition off. Replace driver-side air bag module. See AIR BAG MODULES under REMOVAL & INSTALLATION. Go to step Turn ignition off. Replace SIR coil. See SIR COIL ASSEMBLY under REMOVAL & INSTALLATION. Go to step Turn ignition off. Remove SIR Driver-Passenger Load Tool (J A) and Load Tool Adapter (J A). Disconnect SDM harness connector. If connector shows signs of corrosion or damage, go to step 12. If connector is okay, go to next step. 10. Using Digital Multimeter (J-39200), measure resistance between SDM harness connector terminals A6 and A7. See Fig. 11. If resistance is not infinite, go to next step. If resistance is infinite, go to step Repair short between circuits 347 and 348. See WIRE REPAIR. Go to step Replace SDM harness connector. Go to step Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under REMOVAL & INSTALLATION. Go to next step. 14. Reconnect all SIR components. Ensure that all components are properly mounted. Clear all SIR DTCs. Go to SIR DIAGNOSTIC SYSTEM CHECK. DTC B0024 : DRIVER DEPLOYMENT LOOP VOLTAGE OUT OF RANGE Circuit Description When ignition switch is turned on, Sensing and Diagnostic Module (SDM) tests deployment loop to check for circuit continuity and shorts to ground or voltage. Conditions For Setting DTC

38 for 300 milliseconds or when high side voltage is less than 2 volts and deployment loop resistance is less than 6 ohms for 300 milliseconds. Action Taken SDM turns on AIR BAG warning light and sets DTC. Conditions For Clearing DTC DTC clears when CLEAR CODES command is issued via scan tool. History DTC will clear or once 255 malfunction free ignition cycles have occurred. Diagnostic Aids Condition could be caused by a short to ground or voltage in circuits 347 or 348. A malfunctioning SDM, SIR coil or driver-side air bag module could also cause condition. NOTE: For circuit number and wire color identification, see WIRING DIAGRAMS. Diagnostic Procedure 1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to SIR DIAGNOSTIC SYSTEM CHECK. 2. Turn ignition off. Disconnect driver-side air bag wire harness-to-sir coil connector, located near base of steering column. If connector shows signs of corrosion, damaged terminals or poor connections, go to next step. If connector is okay, go to step If harness side of connector is damaged, replace harness connector. See WIRE REPAIR. Go to step 20. If SIR coil side of connector is damaged, SIR coil must be replaced. See SIR COIL ASSEMBLY under REMOVAL & INSTALLATION. Go to step Reconnect driver-side air bag wire harness-to-sir coil connector. Ensure Connector Position Assurance (CPA) clip is installed correctly. Turn ignition on. Using scan tool, check for SIR DTCs. If DTC B0024 is retrieved, go to next step. If DTC B0024 is not retrieved, go to DIAGNOSTIC AIDS. 5. Turn ignition off. Disconnect driver-side air bag wire harness-to-sir coil connector. Install SIR Driver-Passenger Load Tool (J A) using Load Tool Adapter (J ) to harness connector. Turn ignition on. Using scan tool, check for SIR DTCs. If DTC B0024 is retrieved, go to step 9. If DTC B0024 is not retrieved, go to next step. 6. Turn ignition off. Remove SIR Driver-Passenger Load Tool (J A) and Load Tool Adapter (J ) from connector. Reconnect driver-side air bag wire harness-to-sir

39 coil connector. Remove driver-side air bag module. See AIR BAG MODULES under REMOVAL & INSTALLATION. Install SIR Driver-Passenger Load Tool (J A) using Load Tool Adapter (J A) to upper SIR coil-to-air bag module connector. Turn ignition on. Using scan tool, check for SIR DTCs. If DTC B0024 is retrieved, go to step 8. If DTC B0024 is not retrieved, go to next step. 7. Turn ignition off. Replace driver-side air bag module. See AIR BAG MODULES under REMOVAL & INSTALLATION. Go to step Turn ignition off. Replace SIR coil. See SIR COIL ASSEMBLY under REMOVAL & INSTALLATION. Go to step Turn ignition off. Remove SIR Driver-Passenger Load Tool (J A) and Load Tool Adapter (J A). Disconnect SDM harness connector. If connector shows signs of corrosion or damage, go to step 18. If connector is okay, go to next step. 10. Using Digital Multimeter (J-39200), measure resistance between SDM harness connector terminal A7 and ground. See Fig. 11. If resistance is not infinite, go to next step. If resistance is infinite, go to step Repair short to ground in circuit 348. See WIRE REPAIR. Go to step Measure resistance between SDM harness connector terminal A6 and ground. See Fig. 11. If resistance is not infinite, go to next step. If resistance is infinite, go to step Repair short to ground in circuit 347. Go to step Turn ignition on, Using Digital Multimeter (J-39200), measure voltage between SDM harness connector terminal A7 and ground. See Fig. 11. If voltage is one volt or more, go to next step. If voltage is less than one volt, go to step Repair short to voltage in circuit 348. Go to step Measure voltage between SDM connector terminal A6 and ground. See Fig. 11. If voltage is one volt or more, go to next step. If voltage is less than one volt, go to step Repair short to voltage in circuit 347. Go to step Replace SDM harness connector. Go to step Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under REMOVAL & INSTALLATION. Go to next step. 20. Reconnect all SIR components. Ensure that all components are properly mounted. Clear all SIR DTCs. Go to SIR DIAGNOSTIC SYSTEM CHECK. DTC B0026 : DRIVER DEPLOYMENT LOOP OPEN Circuit Description When ignition switch is turned on, Sensing and Diagnostic Module (SDM) tests deployment loop